A Bluetooth (registered trademark) wireless technology is peer to peer (P2P) communications, and enables communication between pieces of equipment which have been paired in advance.
Furthermore, Bluetooth communication is performed in units of a piconet. A piconet can be configured by one piece of master equipment and seven pieces of slave equipment at maximum simultaneously.
Patent Document 1 listed below describes that a state of communication between a master and a slave is periodically monitored and the master and the slave are changed as needed.